[TowerTalk] Rohn loading

Folks,
A week or so back, there was a thread concerning MA550 tubular
tower loading and strength, compared with triangular tower.
It appears that I'll have a choice between Rohn 25 and a MA550
tower. Looking for 65', actually, so it may be an MA770.
The load will be a 3 el Steppir yagi, @ 5.5 sq. ft.
I can bracket Rohn 25G @ 10 and 25', and hinge the base for
easy tilt-over. Same for the tubular. Question is this:
How high above the house bracket can one safely go with unguyed
25G and the aforementioned load?
Jim, n2ea